1. Field of the Invention
This invention pertains to a cryogenic surgical tool that is used specifically in dermatology for freezing benign and malignant lesions. The cryogenic surgical tool is used in cryosurgery which is one method for removing lesions by destroying tissue through a rapid reduction of temperature having a resulting tissue destruction. In particular, this invention relates to a cryogenic surgical tool where an absorbent member absorbs cryogenic liquid and is then inserted within a housing member. Further, this invention directs itself to a cryogenic surgical tool wherein a low conthermal conductivity handle member is threadedly secured to a housing member within which is captured an absorbent member having cryogenic liquid contained therein.
2. Prior Art
Cryogenic surgical tools adapted for cryosurgery are well-known in the art. In some prior art cryosurgery, Q-tips having a cotton ball that is rolled on the tip are dipped in liquid nitrogen. Such prior art methods of cryosurgery are deficient in that the diameter between one tip and another differs greatly and there is a lack of consistency as to the diameter of the diameter tip being applied to tissue.
In other prior art, pressurized canisters are used that release a cryogenic spray which touches the lesion on the mammalian body. In such prior art systems, spray tips have various sizes and are not easily controlled in the spray area. Generally, such prior art systems necessitate large canisters which have a tendency of psychologically impairing the patient prior to the cryosurgery.
The best prior art known to the Applicants include U.S. Pat. Nos. 4,327,733; 3,455,304; 3,434,477; 3,421,508; 3,736,937; 3,827,436; 3,259,131; 4,345,598; 4,377,168; 3,532,094; 3,702,114; 3,739,956; 3,736,936; 3,736,769; 3,794,039; 3,618,610; 4,457,308; 4,201,319; 4,207,897; and, 4,528,979.
In some prior art systems such as that shown in U.S. Pat. No. 4,327,733 there is provided a cryoenucleation tool having a spoon with a handle and a bowl. A loop is positioned to surround a tumor and liquid nitrogen flows through a coupling into the end of the tubing and around through the loop and then through an end portion to vent to the atmosphere. Such systems do provide for a tool which contiguously contacts a portion of the patient's body with liquid nitrogen passing around however, such utilizes a flowing mass of liquid nitrogen and does not provide for a simple easily dipped absorbent material within which coolant is applied and then capped for contiguous interface with the user's body.
In other prior systems such as U.S. Pat. No. 3,455,304, there are provided cryoextractors which have a thermally conducting cryoextractor tip mounted in one end of a casing and extending therefrom for interface with a patient's surface tissue. However, such systems do not provide for absorbent material which is the main heat transfer device of the subject concept.